Definitely. Thanos kills half the universe in the comics. It was a moment that shocked readers and had far-reaching consequences for the comic's narrative and future developments.
Sure did. Thanos is known for causing a lot of destruction and taking lives in the comic universe. His actions often have major consequences for the heroes and the overall story.
Yes. Thanos' clashes with the Avengers in the comics led to the demise of some members. His might and strategic thinking gave him the upper hand in these battles.